Independently steerable wheel suspension and the straight line mechanism therefor



. J. J. CHAPMAN 2,146,418 INDEPENDENTLY STEERABLE WHEEL SUSPENSION AND THE STRAIGHT LINE MECHANISM THEREFOR Filed July 31, 1934 4 Sheets-Sheet 1 INDEPENDENTLY STEERABLE WHEEL SUSPENSION AND THE STRAIGHT LINE MECHANISM THEREFOR Filed July 31, 1954 4 Sheets-Sheet 12 Feb. 7, 1939.-

' J J. CHAPMAN 2,146,418

WfineSS v In z/cnimf" I Feb. 7, 1939. .1. J. CHAPMAN 2,

INDEPENDENTLY STEERABLE WHEEL SUSPENSION AND THE STRAIGHT LINE MECHANISM THEREFOR Filed July 51, 1934 4 Sheets-Sheet 3 q m w J J. CHAPMAN I 2,146,418

INDEPENDENTLYSTEERABLE WHEEL SUSPENSION AND THE STRAIGHT LINE MECHANISM THEREFOR Filed July 31, 1934 4 Sheets-Sheet 4 Feb. 7,1939,

Fig.4:

S r Davey M07". MAT/1686.

Patented Feb. 7, 1939 QFFI E INDEPENDENTLY STEERABLE WHEEL SUS- PENSION AND THE-S R IGHT ME H- ANISM THEREFO v James ludson Chapman, Elizabeth, La.

Apnliaticn 'July 31, 1934; stern N6. 137 1 C (cizso sezi- An object of my invention is the productioncf an all pivotally mounted vehicle wheel suspension that will allow atwheel mounted thereonto act independently of its companion wheel in its road,or spring, action, and while, allowing freedom of movement substantially. perpendicular to the base of: the vehicle except for the outward tilt of the wheelwhilel-rounding acurve, deliberately produced by tilted steeringpins, or trunnions,

1o, maintains the line of travel of the said-wheel, while so acting, in a straight line substantially perpendicular to the base of the said vehicle and parallel to that of its companion wheel, thus main:- taining the-linesoftravel of the said wheels'at 1g; asubstantially fixed distance, one from the other, thereby greatly reducingthe usual gyroscopic dis= turbances and side-sway, and producing improved steeringand driving conditions. 1

Another important object. of my" invention is 20 to eifecttheeliminatio-n of any direct connection betweenthe steerin'g rods 'and thespindle-body and thereby effecting the elimination of wheel wobble and shock in the steering mechanism, caused by the vertical travelof the wheel when 25 one end of the said rods is directly connected to the said spindle-body.

Anotherobject of my invention is to provide an axle having a substantially U-shaped endxfor the reception of a steering-shell and an upper andya 30 lower fork arm,capertured for steeringpins for flexibly connectingthe said steering-shell to the saidaxle. a a Another important object of my invention is to provide a" steering-shell, the said steering-shell being recessedinone side for the reception of a coil spring, and a lower spring seat thereforprojectingthereinto from a spindle-body, an upper seat for the said spring being provided in the upper end of the said steering-shell, the said steering-shell being substantially vertically apertured at its ends for steering pins for pivotally connecting the said steering-shell to the above described axle, and: horizontally aperturedat each end for flexibly connecting the said steeringshell to a spindle-body and means provided,,preferably on its rear side, for attachment thereto of a steering arm.

Another object of my invention is to provide a spindle-body having a spindle cast integrally 50 therewith, or otherwiserigidly attached'thereto,

" to which a wheel assembly, not shown inthe drawings, is revolvably attached, the said spindlebody having a seat projecting into the above mentioned steeringeshell for the lower end of a 55 coil spring, and two upper and two lower fork arms, the said fork arms being horizontally apertured; for; flexibly (connecting the said. spindlebody 1th the :above :mentioned steering-Shel through meansmrovidedtherefor. 1

4 Another obiectcflmy invention is to provide a 5 coillspring having-its loweruend mounted in, a seat projectingsiroma spindle-body into an open side of asteering-shell and its upper ;end bearing upwardly imaseat ;in;-rthe upnerend of .the said steering-shell to, flexibly sustain its loadhq Anotherw important :object of- {my invention is to provide means for makingsuch pivotal .connection; 10f the, above described. spindle-body .to the above :described steering-shell aswill allow the said-spindle-ibody to move freely; inits road, or spring,; action, while maintaining the said spindleebocly, during-said action, except for the outward :tilt "of the wheel when rounding a. curve,

in 1a,,straightline of travel, or path, substantially perpendicular to ,thevbasegot the vehicle to which it is attachedgl-and maintaining the path ofthe wheel which iszmountedcn the said spindle-body, parallelz-to, and acfixed distance from, a similar path of its companion wheel. l t

Other objects and advantages of my invention will-be apparent duringthe eourse of the following.detailed:descriptionm,l

- In-th'eL accompanying drawings, forming a part of this specification, and .in, which like-reference characters'rdesignate like partsthroughout the Same-1 i :1 f Y-Y ,1

Figure 1 is the rear elevationof an independently acting, all pivotally mounted, straight line travel,independently. steerable automotive front wheel suspension-showingits movable members in thecenter ofltheir, travel. l

- Figure 2 islarhorizcntal section taken substantially-on'ithe lined-7450f :Figure 1, the lower link assembly notrbeing showna. a Figure 3 is a? horizontal section taken substan- 40 tia'lly on the line3 -.-.3: of Figure 1, the upper link assembly not beingershowms Figures isaa vertical section taken on the line 44 oflI'igure-ZM V In the drawings, wherein for the purpose of 5 illustration; is shown apreferred.embodiment of my invention, the numeral fitdesignates an axle, one end .thereoi only being shown, the said end having aniupper and lower fork arm ,21, 28 definin a: substantially -..U: -1.shepe 0pen ng, for he 0 receptionloi; aistee -n rsh lc m mb r a of thefork arms! is apertured-for the upper and lower steering pins lt-and 15 respectively, the said pins l4 and; l 5 gpivotally-connecting the said steering-shellac thesaid axle, the intermediate portion of the said axle being of any suitable construction for attachment to the particular vehicle on which it is used.

In Figs. 1, 2, 3 and 4, is shown steering-shell 5, recessed in one side for the reception of a coil spring I6 and for a lower spring seat I2a therefor projecting thereinto from a spindle-body l2, an upper seat 5a for the saidspring being provided at the upper end of the said recess, the said steering-shell having bifurcations at its ends for the reception of the upper and lower fork arms 21, 28 of the axle 6, and apertures at each end for the steering pins I4 and I5 for pivotally connecting the said steering-shell 5 and the axle 6, the said pins I4 and I5 in practice being rigidly secured to the steering-shell 5 with taper pins 40, 4|, the said steering-shell 5 being horizontally apertured at its upper and lowerends'for the pins I1 and I8 respectively for flexibly connecting the said steering-shell, through suitable means, to a spindle-body l2;

'The spindle-body I2 has a spindle I I cast integrally therewith, or otherwise rigidly attached thereto, the said spindle-body having a seat l2a projecting into the above mentioned steeringshell for the support of the lower end of a coil spring I6. Two upper and two lowerfork arms 29, 30 are horizontally apertured for'the pins 2i and 22 respectively, for flexibly connecting the said spindle-body I2 to the above mentioned steering-shell 5 through means provided therefor and presently described.

, The above mentioned meansfor flexibly connecting the above des'cribedspindle-body I2 to the above described steering-shell 5, that will admit of a substantially vertically reciprocating motion in the said spindle-body in a relatively straight line or path parallel to the said steeringshell, while otherwise maintaining the said'spindle-body in its relative position to the'said steering-shell, consists of the following structure. An upper link I is bifurcated at32w (Fig. 2) for the reception of the fork arm 2Ilof the axle 6 and the steering-shell 5. The upper link'l has two fork arms 3| (Fig. 2), which are disposed at the sides of the steering-shell 5 and are horizontally apertured for the reception of the pin'l'I for pivotal connection with the upper end of the steering-shell 5. The opposite end of the said link I is horizontally apertured for thereception of the pivot pin I9 and for the pins 23 and 24 (Fig; 2). A lower link 8 (Fig. 3) is bifurcated at 33 for the reception of the fork arm 28 of the-axle 6 and the steering-shell 5. Said link has two fork arms 34 which are disposed at the sides of the steeringshell 5 and are horizontally apertured for the reception of the pin l8'for pivotal connection with the lower end of the steering-shell 5. The opposite end of the said link 8 is horizontally apertured for the reception of the pivot pin 20. An upper link 9 comprises two arms, each of the said arms being apertured at one end for the reception of the pivot pin I9, to which they'are rigidly secured by taper pins or bolts 36,the said pin I9 forming a pivotal connection between the links I and 9, the said arms of the link 9 being disposed about the link I, the opposite ends thereof being vertically slotted at 35 for the reception of the upper fork arms 29 of the spindle-body l2 and being horizontally apertured for the reception of the pins 2| for pivotal connection with the upper arms of the spindle-body l2. A'lower link In of substantial U shape has two arms which are disposed about the lower link 8(Fig; 3) one end of the said lower link I9 being'ho'rizont'ally apertured for the reception of the pins 20, 25 and 26. the said pin 29 being rigidly secured thereto by taper pins, or bolts 31', and forming a pivotal connection between the links 8 and II]. The opposite ends of the said arms are vertically slotted at 38 for the reception of the lower fork arms 30 of the spindle-body l2, and horizontally apertured for the reception of the pins 22 for pivotal connection with the lower fork arms of the spindle-body I2. Two pairs of crossed links I3, are

horizontally apertured at each end for the reception of the pins 23, 24 (Fig. 2), 25 and 26 (Fig. 3),

to which they are rigidly secured with pins, not shown, one pair of the said crossed links being connected at their upper ends with the pin 23 to the upper link 1, their opposite ends being pivotally connected through the pins 26 to the lower link I 0. The other pair of the said crossed links is pivotally connected at their upper ends through the pin 24 to the upper link I, their opposite ends being pivotally connected through the pin 25 to the lower link III.

In this disclosure, it will be seen that the links I, 8, 9 and I0 have equal pivotal lengths, and by reference to Figure 1 of the drawings, it will be seen that, with all parts thereof in their intermediate positions, all pivotal connections in the upper link assembly I and 9 lie in the same horizontal plane, that all pivotal connections in the lower link assembly 8 and I0 lie in the same horizontal plane, that all pivotal connections in the upper link assembly I and 9 are the same distances from similar pivotal connections in the lower link assembly 8 and I9, that the two pairs of crossed links I3 have the same pivotal lengths, and the pivotal distance from the pin 23 to the pin 24, with the pin I9 as a center, is equal to the pivotal distance from the pin 25 to the pins 26, with the pin 20 as a center. The above described arrangement of parts and relative pivotal distances is a preferred construction but desirable changes which do not depart from the spirit of my invention may be made.

It will .now be seen by referring to Figure 1 of the drawings that, as the pivotal connections 2| and 22 of the links 9 and I9 move upwardly with the spindle-body I 2, and the pivotal connections I! and I8 of the links 1 and 8 remain relatively stationary with the steering-shell 5, the pins 25 and 26 will move in counterclockwise arcs about the pivotal center 29, that the pins 25 and 26 being connected through two pairs of crossed links I3 to the pins 24 and 23 respectively in the link I, that the pins 24 and 23 will be caused to move in equal clockwise arcs around the pivotal center I9.

It is now evident that the action of the crossed links I3 will cause the links I and I0 at all positions in their vertical travel to form like angles from horizontal bases, but in opposite directions, that, as the link I is caused to move around the movable center I9 while the pivotal connection I'I remains stationary, the movable center I9 is caused to move upwardly in a vertical plane in a clockwise are about the center I'I. As the pin 20 is maintained constantly at a substantially fixed distance from the pin I9, the pin 20 will also describe a clockwise arc in a vertical plane about the center I8. The link 9, being pivotally connected at one end to the upper end of the spindle-body I2, its opposite end being pivotally connected to the link I, is maintained constantly at the same angle from a horizontal base as that of the link I ll. Therefore, as the spindle-body I2 moves upwardly the pivot pins I9 and 29 describe clockwise arcs in asubstantially vertical plane about the centers I! and iii-respectively, and the pins 2| and '22 move in a vertically straight line 'as' they describe equal counterclockwise 'arcsabout the m vable centers i9 and 20 respectively, therefore, as the displacement of IQ and 2B in the first mentioned arcsare, at all points, equal to the displacement, but in opposite directions of pins 2| and 22 in the last mentioned arcs, the spindle-body l2, if moved in ,a vertically reciprocating manner, will travel in a relatively straight line, or path, parallel to the steering-shell to whichit is flexibly attached.

When the spindleebody l2 moves below its intermediate position the above described action is repeated in an opposite direction.

It is now seen, in theeombination of parts in my invention, that the axle ,6, with its steering pins, or trunnions l4 and I5, is, a relatively fixed member, the other members thereof being movable in a substantially horizontally circular swinging motion aboutthe-steering pins I4, [5,

or trunnions l4 and [5, in the said axle.

With further reference to'thestraight line action mechanism, above, described, it is shown that the straight line action is producedby two pairs of links, or their equivalents, acting in opposite directions, one pair of links thereof counteractingthe actionof the otherpair of links, the said opposed motion being produced in its simplest and most practical form by the crossed links l3. If the links-liare made relatively shorter, the reciprocally movable member. {2 will be caused to travel in a convexed arc. If the links l3 are made relatively longer, the reciprocally movable member l2 will be caused to move in a concaved arc.

By referring again to the drawings, it will be seen that there is no direct connectionbetween the steering mechanism of the vehicle, to which my invention is attached, and the substantially vertically reciprocating,spindle body l2, there being an intermediatemember positioned between the said spindle-bodyylZ-and the above described axle 6, the said spindle-body l2-being soconnected to theksaid intermediate member 5 as to admitof itssubstantiallyperpendicular travel, parallel to the said intermediate member 5,.the said intermediate member 5 being also connected through steeringpins l4 and 15 to the axle'ii and a connection for the above mentioned steering mechanism provided on the intermediate memberi at 39 in Figure 1 through i which to actuate :the saidintermediate memher 5.

To assemble myinvention, progressively, place the steeringshell 5 in position in the axle 6,

place the ball thrust bearing in position, insert the pin l4 and secure the pin 14 rigidly to the steering-shell 5 with taper pins or bolts 49; insert the pin l5 and secure it 'tothe steering-shell 5 with taper pins or bolts14i; place the link 8 in position and insert the pin 18 and secure the ,pin 18 rigidly to the link 8 withtaper pins or bolts 42; place the link :Hlinposition, insert the pin 29 and secure the said pin '20 to the said link ill with'the taperpins or bolts 31; place the link I in position andinsertthe-pin l1 and secure the said pin ll rigidly to thelink 1 with taper pins or bolts 43; insert the pins 24 and 25 and press thereon a pair of links [3 andsecure the said links H rigidly to, the said pins 24 and 25 in any suitable manner; secure, the ends of the other pair of links 13 tothe link with the ins'zs and suitably secure the pins 26 rigidly to the links I3, and insert the pin 23 in the link I and press the upper ends of the said links l3 thereon and rigidly suitably secure the said links to the said pin 23; insert the pin l9 in the link 'i, press the arms of the link 9 onto the pin I9 and secure the said arms rigidly to the pin I9 with the taper pins or bolts 36; place the spring IE on its seat [2a on the spindle-body l 2, in sert the spring and said seat into the open mear the steering-shell Band place the spindle-body [2 in position; insert the pins 22 and secure them rigidly to the link i0 with taper "pinsfor bolts 44; insert the pins 2| and secure them rigidly to the link 9 with taper pins or bolts 45. i

i To disassemble my inv'ention' reverse the above proceeding.

above stated, while this specification has especial :reference to automotive front wheels, my invention is intended for various other uses fo rfwhich it is adaptable and when used for nonsteerable, or other wheels not requiring the steering-shell, the said steering-shell 5, with its steering connections, may be eliminated and the spindle-body l2 may beattached directly to the axle 6 in a manner similar to the way it is now attached to the steering shel1 5.

I have shown the pivotal connections in my invention fitted with a commonly used type of pivotal pinsand bushings, thesaid pivotal pins being secured in theirrelative positions by tapered pins, or tapered bolts, through tapered holes drilled therefor, the said tapered holes preferably being 'drilledpartlyin the said pivotalpins and partly in the members to which they are rigidly attached. It is understood, however, that as my ilnvention' is intended for use on various kinds ofvehicles, as well as other uses for whichit is adaptable, the said pivotal pins, bushings and taper pins may have any of the well known equivalents substituted therefor, and that such changesas are necessary for adapting my invention to its various requirements, without departing from the spirit of my ihvention rnay be made.

In this specification, one wheel suspension only is shown, itbeing understood that its companion wheel suspension is similar, but con structed in an opposite direction, the intermediate portion of the axle thereof being of any suitable construction for the particular ,vehicle on which it is used.

Having now described my invention and ascertained its functione what I claim is:

1. In a vehicle wheel suspension, the combination with a frame, of a steering member, and means supporting said steering member on said frame for swinging movement in .a generally horizontal plane, the said; means comprising a steering pin between the frame and steering member, a wheel carrying injeniber for a steerable road wheel, and means connecting said Wheel carrying member tofan adjacent steering member for rising and falling movement with respect thereto, for maintaining the said road wheel in straight line, parallel, vertical path during such movement the said means also com prising a plurality of links, each having articulated connection with the said steering member and extending inwardly therefrom for swinging movement in a generally transverse vertical plane and a plurality of links each having articulated connection with the first links and extending outwardly there-from and having articulated connection" with'the said wheel carrying member for swinging movement in a generally transverse vertical plane with relation to said vehicle when said steering member is in a mid position, and means mounted on the inner ends of the first and second pluralities of links for guiding them synchronously in opposite directions, the lateral movement of the first links counteracting the lateral movement of the second links. a

2. In a wheel suspension, the combination with a frame, of a steering member having articulated connection with said frame, a wheel carrying member, means connecting said wheel carrying member to said steering member for rising and falling movement in a straight line, substantially vertical, path with respect thereto, said means comprising a pair of vertically spaced links having articulated connection with said steering member and extending inwardly therefrom for swinging movement in substantially vertical planes and 'a pair of vertically spaced links having articulated connection with said Wheel carrying member and extending inwardly therefrom for swinging movement in substantially vertical planes, when said steering member is in a mid position, and articulated connections between the inner ends of the upper and of the lower links respectively, and means mounted on the inner ends of the first and last links for maintaining them at substantially like but oppositely directed angles to a horizontal plane, the said means comprising a pair of crossed links, each having articulated connections with one frame connected link and one Wheel carrying member connected link.

' wheel carrying member to said steering member for rising and falling movement with respect thereto, said means comprising a pair of vertically spaced links' having pivotal connections with said steering member and extending inwardly therefrom for swinging movement in substantially vertical planes and a pair of vertically spaced links having pivotal connections with said wheel carrying member and extending inwardly therefrom for swinging movement in substantially vertical planes when said steering member is in a mid position, and pivotal connections between the inner ends of the upper and of the lower links respectively, and. means mounted on the inner ends of the first and last links for maintaining them at like but oppositely directed angles to a horizontal plane, the said means comprising a pair of'crossed links, each having pivotal connections with one steering member connected link and one wheel carrying member connected link.

4. In a wheel suspension, the combination with a wheel carrying member, of a member fixed with relation thereto, and means connecting said wheel carrying member to said fixed member for rising and falling movement with respect thereto, in a substantially vertical straight line path, the said means comprising a pair of links having pivotal connections with said fixed member and extending inwardly therefrom for swinging movement in generally vertical planes and a second pair of links having pivotal connections with said wheel carrying member and extending inwardly therefrom for swinging movement in generally vertical planes, and pivotal connections between the inner ends of the upper links and of the lower links of each pair respectively, and

means mounted on the first and second links for maintaining them at substantially like angles but oppositely directed from a horizontal plane, the said means comprising crossed links, each having pivotal connections in the pivotal planes of one fixed member connected link and one re ciprocating member connected link, and means between the said wheel carrying member and the said fixed member to flexibly sustain its load.

5. In a straight line mechanism, the combination with a reciprocating member, of a member fixed with relation thereto, and means connecting said reciprocating member to said fixed member for guiding it in a substantially straight line path, said means comprising a pair of links having pivotal connection with each other at one end, the opposite end of one link thereof having pivotal connection with said fixed member and the opposite end of the other link having pivotal connection with said reciprocating member, and a second pair of links having a pivotal connection with eachother at one end, the opposite ends of the respective links being pivoted to the fixed and reciprocating members, the pivotal connections of the first and second pairs of links lying on substantially parallel axes, the pivotal connections of said pairs of links to the respectivefixed and reciprocating members being substantially in the same vertical plane, and the pivotal connections of each pair of the said links being in planes substantially at right angles to said vertical plane when in mid positions, and means mounted on the first and second links for maintaining the fixed member connected links and the reciprocating member connected links at like but oppositely directed angles from their mid positions, the said means comprising crossed links, each having pivotal connection with one of the fixed member connected links and one of the reciprocating member connected links, the said connections being substantially equally spaced from the pivotal connections of the first and the second links.

6. In a vehicle wheel suspension, the combination with a frame, of a steering member, and means connecting said steering member to said frame for swinging movement in a generally horizontal plane, said means comprising articulated connections therebetween, a wheel carrying member, and means connecting said wheel carrying member to said steering member for guiding it in a straightline path substantially parallel to the longitudinal and transverse vertical planes of the said vehicle when said steering member is in the mid position, said means comprising articulated connections between the steering member and wheel carrying member, including two sets of links for swinging movement substantially parallel to the transverse vertical plane of the said vehicle, means mounted on said two sets of links for guiding their movements in opposite directions, and means between the said steering and wheel carrying members for elastically supporting a load.

'7. In a mechanism for guiding a reciprocating member in a predetermined path, the combination with said reciprocating member, of a member fixed with relation thereto, and means connecting said reciprocating member to said fixed member, the said means comprising a pair of linkshaving pivotal connections with the said fixed member and a pair of links having pivotal connections with said reciprocating member and the first said links for swinging movement generally in the same plane, the said pivotal connections lying on substantially parallel axes, the

. connections in the fixed member and in the remciprocating member being substantially in the ...:same-p1ane andthe pivotal connections in the saiddinksbeingin planesat rightangles to the.

first said plane when in mid positions, and means. mounted on the first and second links forguiding them synchronously in opposite directions.

8. In a vehicle wheel suspension, the combination with a frame, of a steering member, means connecting said steering member to said frame, a wheel carrying member, and means connecting said wheel carrying member to the steering member for rising and falling movement with respect thereto in a straight line path, substantially parallel tothe longitudinal and transverse vertical planes of the said vehicle, the said means comprising a pair of vertically spaced links having pivotal connections with said steering member and extending inwardly therefrom for swinging movement in generally vertical planes, a pair of vertically spaced links having pivotal connections with the inner ends of the first said links and extending outwardly therefrom and member in a predetermined path, the combination with said reciprocating member, of a member fixed with relation thereto, and means connecting said, reciprocating member to said fixed member, said means comprising a pair of links having pivotal connection with said fixed member, a pair of links having pivotal connections with said reciprocating, member and with pivotal connections, with the first -named pair of links for swingingmovement, and crossed means connecting the pairs of links at opposite sides of the last named pivotal connections for guiding. the swinging of said pairs of links synchronously in opposite directions.

10. In a mechanism for guiding a reciprocating member in a predetermined path, the combination with said reciprocating member, of a member fixed with relation thereto, and means connecting said reciprocating member to said fixed member, the said means comprising a pair of links having pivotal connections with the said fixed member and a link having a pivotal connection with said reciprocating member and one of the first said links for swinging movement, the said pivotal connections lying on substantially parallel axes, the connections in the fixed member and in the reciprocating member being substantially in the same plane and the pivotal connections in said links being in planes at right angles to the first said planes, when in their mid positions, and means mounted on the first and second links for guiding them synchronously in opposite directions.

JAMES JUDSON CHAPMAN. 

